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Wednesday, April 20, 2016

Out of Reach Without Nuclear and Shale

US emissions reduction goals for 2025 could not be achieved without nuclear power and the fracking technology necessary to extract shale gas.

Recent revisions by the EPA in its estimates of methane leaks from natural gas production and use do not negate the benefits of gas in reducing emissions.

In its lead editorial yesterday, the Washington Post took presidential candidate Bernie Sanders to task for his attacks on nuclear power and natural gas. The Post focused its critique on greenhouse gas emissions and the emissions trade-offs involved in substituting one form of energy for another. That speaks directly to one of the main reasons that Mr. Sanders' argument resonates with his supporters, but it ignores an even more basic problem. The energy contribution from shale and nuclear power is so large that if our goal is a reliable, low-emission energy mix that meets the future energy needs of the US economy, we simply cannot get there without them, at least not in any reasonable timeframe.

The pie chart below shows the current sources of US electricity in terms of the energy they generate, rather than their rated capacity. This is an important distinction, because the renewable electricity technologies that have been growing so rapidly--wind and solar--are variable and/or cyclical, generating only a fraction of their rated output over the course of any week, month, or year.

For example, replacing the output of a 2,000 megawatt (MW) nuclear power plant such as the Indian Point facility just north of New York City would require, not 2,000 MW of wind and solar power, but between 7,600 MW and 9,400 MW, based on the applicable capacity factors for such installations. Now scale that up to the whole country. With 99 nuclear reactors in operation, rated at a combined 98,700 MW, it would take at least 375,000 MW of new wind and solar power to displace them. As the Post's editorial points out, money spent replacing already zero-emission energy is money not spent replacing high-emitting sources.

At the rates at which wind and solar capacity were added last year, that build-out would require 24 years. That's in addition to the 36 years it would take to replace the current contribution of coal-fired power generation. It also ignores the fact that intermittent renewables require either expensive energy storage or fast-reacting backup generation to provide 24/7 reliability.

That brings us to natural gas, the main provider of back-up power for renewables, and the "fracking" (hydraulic fracturing) technology that accounts for half of US natural gas production. Fracking has transformed the US energy industry so dramatically that it is very hard to gauge the consequences of a national ban on it, even if such a policy could be enacted. Would natural gas production fall by a third to its level in 2005, when shale gas made up only around 5% of US supply, and would imports of LNG and pipeline gas from Canada ramp back up, correspondingly?

Or would production fall even farther? After all, one of the main factors behind the rapid growth of shale gas in the previous decade is that US conventional gas opportunities in places like the Gulf of Mexico were becoming scarcer and more expensive to develop than shale, which was higher-cost then than today. Either way, the constrained supply of affordable natural gas under a fracking ban would not support generating a third of US electricity from gas, vs. 20% in 2006. So we would either need even more renewables and storage--in addition to those displacing nuclear power--or, as Germany has found in pursuit of its phase-out of nuclear power, a substantial contribution from coal.

One of the primary reasons cited by Mr. Sanders and others for their opposition to shale gas, aside from overstated claims about water impacts, is the risk to the climate from associated methane leaks. Here he would seem to have some support from the US Environmental Protection Agency, which recently raised its estimates of methane leakage from natural gas systems.

Methane is a much more powerful greenhouse gas than carbon dioxide (CO2), so this is a source of serious concern. However, a detailed look at the updated EPA data does not support the contention of shale's critics that natural gas is ultimately as bad or worse for the climate than coal, a notion that has been strongly refuted by other studies.

The oil and gas industry has questioned the basis of the EPA's revisions, but for purposes of discussion let's assume that their new figures are more accurate than last year's EPA estimate, which showed US methane emissions from natural gas systems having fallen by 11% since 2005. On the new basis, the EPA estimates that in 2014 gas-related methane emissions were 20 million CO2-equivalent metric tons higher than their 2013 level on the old basis, for a year-on-year increase of more than 12%. This upward revision is nearly offset by the 15 million ton drop in methane emissions from coal mining since 2009, which was largely attributable to gas displacing coal in power generation.

In any case, the new data shows gas-related emissions essentially unchanged since 2005, despite the 44% increase in US natural gas production over that period. The key comparison is that the EPA's entire, updated estimate of methane emissions from natural gas in 2014, on a CO2-equivalent basis, is just 2.5% of total US greenhouse gas emission that year. In particular, it equates to less than half of the 360 million ton per year reduction in emissions from fossil fuel combustion in electric power generation since 2005--a reduction well over half of which the US Energy Information Administration attributed to the shift from gas to coal.

In other words, from the perspective of the greenhouse gas emissions of the entire US economy, our increased reliance on natural gas for power generation cannot be making matters worse, rather than better. That's a good thing, because as I've shown above, we simply can't install enough renewables, fast enough, to replace coal, nuclear power and shale gas at the same time.

What does all this tell us? Fundamentally, Mr. Sanders and others advocating that the US abandon both nuclear power and shale gas are mistaken or misinformed. We are many years away from being able to rely entirely on renewable energy sources and energy efficiency to run our economy. In the meantime, nuclear and shale are essential for the continuing decarbonization of US electricity, which is the linchpin of the plans behind the administration's pledge at last December's Paris Climate Conference to reduce US greenhouse gas emissions by 26-28% by 2025. That goal would be out of reach without them.

10 comments:

In 7 times more dense populated Germany (226 vs 32people/km2) the share of nuclear was 29% in 2000. In 2015 it was 15% and it will be zero in 2023.

So: - nuclear decreased from 170Twh in 2000 to 92TWh in 2015- coal decreased from 291 TWh in 2000 to 273 TWh in 2015 - gas decreased from 89 TWh in 2000 to 60 TWh in 2015While - renewable increased from 104TWh in 2010 to 196TWh in 2015

Of course coal decrease could have been faster and nuclear decrease less fast, but most Germans and their scientists consider nuclear to be far more dangerous.

This occurred despite the extremely high prices of wind+solar in the first decade of this century. For any country starting now the costs will be factors lower due to the price decreases of solar+wind+storage (battery+P@G for seasonal storage).

These are very useful figures to consider. Based on the 2015 numbers you provide, renewables were just under 25% of total generation in Germany last year, though this presumably includes hydro and biomass, which unlike wind and solar are dispatchable, baseload technologies. I would also note that the entire German electricity output is roughly the size of the US nuclear sector alone, so there is an important difference of scale.

Scale and geography differentiate Germany and the US in other ways, too. Germany's population density is an advantage, since it means that renewable resources are generally close to markets, compared, for example, to some of the best US wind resources in the western plains, or the best US solar resources in the southwest.

It's also the case that Germany is surrounded by other, comparably-sized electricity markets to which it is interconnected. This enables excess German wind and solar to be pushed out to neighboring countries avoiding curtailment such as occurs in Texas and other markets in the US. It also enables Germany to pull in French nuclear and Scandinavian hydro when wind and solar come up short.

Germany still has a ways to go know if achieving 100% renewables will be feasible. Empirical research suggests that the task will grow harder as wind and solar's shares approach their capacity factors, so in Germany that would be around 40-45% combined wind and solar. Let's see what the country's energy mix looks like once it passes that hurdle. Current US Department of Energy studies see the potential for 30% wind, here. Solar would vary more by region, since we have places like the southwest with 2-3x the generally weak solar resource of Germany, and others like New England with sun little better than yours.

I've been watching the German experiment with great interest from the start. Of course it shouldn't be surprising what changes you can prompt when you start out by offering developers up to $1.00 (equivalent) per kWh for solar.

Germany's position, size and population density is a major disadvantage as:- it doesn't have the plains for wind and US high insolation.- the high population density generate a lot of NIMBY against wind turbines, etc.

Im-/export is relative small (partly due to low interconnection capacities).So the Germans also curtail wind and solar (grid management can do it directly without interference of the owners), and negative whole sale prices at their power exchange in Leipzig are not uncommon nowadays (you can view those at the exchange-site).

They are developing Power-to-Gas (P2G) plants for a.o. seasonal storage (storing gas in earth cavities is cheap). Those are intended to operate only when the whole sale price is very low. So they may contribute to a power price bottom at the exchange.

They have already ~20 pilot plants (utilizing different technologies) at typical ~6MW each. All unmanned, most housed in a few containers. So easy transportable and low operational costs.

Part of their entrepreneurs envisage to place those at car refilling stations for the coming hydrogen cars.

Yes Germany has a long road ahead towards 100% renewable, though it is (with energy efficiency) clearly the only viable option now.Also shown by France who:- targets to reduce its nuclear share to 50% in 2025; and- whose government institute ADEME calculated that 100% renewable in 2050 is only slightly more expensive than the cheapest option being 80% renewable (40% renewable allowing for more nuclear is just as expensive as 100% renewable). You can play with the options at:http://mixenr.ademe.fr/en

"Empirical research suggests that the task will grow harder as wind and solar's shares approach their capacity factors".Yes but by far not so much as the Hirth studies suggest. His studies support the portfolio of his employer Vattenfall. While he works in Berlin, his results are nearly ignored in Germany, also because similar studies by think tank Agora (and in the nineties) show different results. The costs shouldn't be exaggerated as shown by the transition towards 100% renewable of islands, etc.

I estimate that P2G will become gradually more important when wind+solar share increase towards ~70% in Germany.

Denmark will be 100% renewable regarding all energy in 2050 (so also for heating and transport). You only can construct an house when you can show that it is energy neutral. They told me that the extra investment is compensated by the near zero utility bill. Danish people belong to the happiest in the world according to UN statistics.

I wouldn't call the German Energiewende an experiment. Considering the many (scenario, etc) studies, it's from the start in 2000 a scientific well thought-out migration towards 80% renewable in 2050. Every ~2 years an adaptation using newest circumstances & insights, etc.The 80% renewable target is already some years under study and in discussion; it may be upgraded towards 90% as the costs of renewable decreased more than predicted.

The $1/KWh Feed-in-Tariff of the first years was because studies concluded that the price of PV-solar would decrease greatly when there would be a mass market. So they created one.The 30% investment subsidy for solar batteries for small rooftop solar (<10KW) owners, tries to do create similar mass market. They expect that battery prices will be decreased so much in ~2020 that they can retract the subsidy as rooftop solar owners will install them anyway.

I think it's fair to consider the Energiewende an experiment in the sense that no large, industrial economy has done what Germany is attempting, and so the results are still subject to significant uncertainties, particularly as they proceed farther. Denmark is an interesting example both for its extent of renewables penetration (mainly wind) and because without its interconnections with much larger adjacent grids able to absorb the fluctuations of wind's intermittency, it couldn't have been done without substantial fossil backup or expensive storage.

Don't get me wrong. I'm happy enough that Germany is undertaking this experiment, and I'm equally glad the US is letting someone else work out the bugs before we attempt it on a continental scale. Either way, the US solution is likely to look different than Germany's, because our circumstances are quite different and more diverse.

This study of Agora, the German think-tank, gives an overview of the very different results of studies regarding the integration costs for high wind+solar shares (50%-65% which implies 60-80% renewable share in Germany).

The key insight chapter shows in a few pages a nice overview of the different points of view. This summarizes the controversy:"As in any other market, entrance of a new producer tends to have a negative impact on the return on investment of existing producers. From the perspective of consumers ... the new entrant may appear as a positive effect if it induces lower power prices ..."

Frankly, Bas, this is interesting but my biggest concerns aren't financial, though that plays a role, too. No one has reached those levels of penetration by intermittent renewables in a major economy, and until someone does--Germany first, presumably--the uncertainties around implementation are bigger than studies like the one to which you refer usually suggest or admit. Lots of assumption at work, there, especially given the huge daily and seasonal swings from solar in a country with such poor insolation.

Thank you.It seems that the leading German scientists feel no such uncertainties about those high levels of wind+solar penetration.

They had at least one study about it some years ago. Couldn't find it now. I remember that the conclusion then was that grid expansion was the cheaper solution.

However that was before:- the major solar price decreases; and - the introduction of cheaper flow batteries; and - the introduction of cheaper / more efficient P2G.So I'm not sure how much that conclusion still holds.